A leading auxiliary switch is known from German Publication DE 197 54 071 C1. The auxiliary switch has an operating slide provided with a link slot which engages with a pivot lever acting upon a contact carrier. In a first operating phase, the contact carrier is pivoted into an ON position in a direction substantially perpendicular to the actuation direction of the operating slide and against the action of a torsion spring acting upon the pivot lever and of contact pressure springs. In a subsequent second operating phase, the operating slide travels further and operates an actuating element of a circuit breaker while the contact carrier remains in the ON position. The link slot has two contour sections which merge into one another at an angle of 80° to 100° and through which a pin projecting from the pivot lever passes during one of the operating phases, respectively. The boundary surfaces of said contour sections, in conjunction with the torsion spring, ensure that the pivot lever is in permanent contact with the operating slide and the contact carrier so as to avoid incorrect positions of the contact carrier.